Definitionone-on-one adverb USIn sports, if something is done one-on-one, it means that each player from one team is matched to a single player from the other team.See also one-to-one (CONNECTION); one-to-one (TWO PEOPLE).

one-to-one (TWO PEOPLE) adjective [before noun] (US ALSO one-on-one)describes an activity in which one person is teaching or giving information to another person:These children have special educational needs and require one-to-one attention.---

one-to-one (CONNECTION) adjectiveSomething that is in a one-to-one relationship with another thing strongly influences the way that the other thing changes:Is there a one-to-one relationship between pay levels and productivity?